Article
Physics, Applied
Sevil Sarikurt, Yusuf Zuntu Abdullahi, Engin Durgun, Fatih Ersan
Summary: This study investigates the thermal expansion coefficients of group III-Nitride monolayers with temperature, revealing high negative values below room temperature and a convergence to zero for certain monolayers above room temperature. The highest contribution to negative thermal expansion comes from the ZA phonon mode. These findings are important for the design of nanoscale heat devices.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Physics, Condensed Matter
Rafael M. Digilov
Summary: The new equation for the temperature dependence of the thermal expansion of solids, presented in terms of the Lambert function, is suitable for a wide class of solids in the entire temperature range and provides linear correlation between thermal expansivity and specific heat according to Gruneisen's law at low temperatures. At intermediate temperatures, the equation simplifies to Gruneisen expressions, and it predicts a sharp increase in expansivity at high temperatures in accordance with experiments.
PHYSICA B-CONDENSED MATTER
(2021)
Article
Chemistry, Physical
Zhao Wang, Cai Cheng, Heng-Xi Zhou, Ke Liu, Xiao-Lin Zhou
Summary: This study investigates the electronic, phonon, elastic, and thermal properties of two-dimensional square-octagon MoS2 (so-MoS2) using first-principles calculations and theoretical analysis. The results show that so-MoS2 has good flexibility, maintains elastic isotropy under twisting and straining, and exhibits promising thermodynamic properties. The study expands the potential for topological material systems.
APPLIED SURFACE SCIENCE
(2021)
Article
Physics, Multidisciplinary
Yilin Zhang, Huimin Mu, Yuxin Cai, Xiaoyu Wang, Kun Zhou, Fuyu Tian, Yuhao Fu, Lijun Zhang
Summary: We developed an algorithm for identifying and characterizing the connection patterns of structural units in open-framework structures and constructed a descriptor set for the thermal expansion properties of this system, which is composed of connectivity and elemental information. Our developed descriptor, aided by machine learning (ML) algorithms, can effectively learn the thermal expansion behavior in small sample datasets collected from literature-reported experimental data (246 samples). Our results demonstrate that developing effective descriptors closely related to thermal expansion properties enables ML models to make accurate predictions even on small sample datasets, providing a new perspective for understanding the relationship between connectivity and thermal expansion properties in the open framework structure.
Article
Materials Science, Multidisciplinary
Sushree Sarita Sahoo, Mayanak K. Gupta, Ranjan Mittal, G. Vaitheeswaran, V Kanchana
Summary: The study investigated the negative thermal expansion behavior and coefficients of Hg2X2 and HgX2 (X=Cl, I) materials, providing important information for device engineering design.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Geochemistry & Geophysics
Lin Liang, Xinjian Bao, Wen Liang, Haipeng Song, Xiang Wu, Shan Qin
Summary: This study investigated the in-situ X-ray diffraction (XRD) and Raman spectra of synthetic (Mg, Fe, Mn)CO3 single crystals. The lattice parameters and volumetric thermal expansion coefficients were obtained, indicating an inherent anisotropy of c/a near to 3.0. The Raman spectra showed a negative temperature dependence similar to the end members. The average thermodynamic Gruneisen parameters for different compositions of (Mg, Fe, Mn)CO3 carbonates were determined.
Article
Crystallography
Wuxueying Qiu, Chang Su, Yonggang Liu, Wei Song
Summary: Based on an iterative numerical approach and experimental data from the literature, we determined the thermodynamic properties of MgAl2O4 spinel, including thermal expansion, heat capacity, entropy, and the Gruneisen parameter, which show nonlinearity and negative correlation with pressure over a wide temperature and pressure range.
Review
Chemistry, Multidisciplinary
Eleonora Isotta, Wanyue Peng, Ashiwini Balodhi, Alexandra Zevalkink
Summary: The elastic behavior of materials is essential for understanding thermal transport in thermoelectrics. This review discusses the importance of measuring the elastic moduli and sound velocity in studying lattice thermal conductivity, bond anharmonicity, and phase transitions. It presents trends in sound velocity, anharmonicity, and thermal conductivity in different classes of thermoelectrics, and highlights the potential of using experimental sound velocities to improve thermal conductivity models. The review also critically discusses the estimation of the Gruneisen parameter from elastic moduli.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
M. S. Omar, Botan Jawdat Abdullah, Ayoub Sabir Karim, Sirwan Karim Jalal
Summary: The specific heat for Si nanoparticles is calculated using the Gruneisen equation, which takes into account lattice thermal expansion, lattice volume, and bulk modulus. The calculated results are comparable to the size dependent lattice volume under hydrostatic pressure. The reduction in specific heat to near zero at the critical size of nanoparticles can be explained by thermal expansion. The study also evaluates the size dependent vibrational frequency, mean square atomic displacement, atomic spring constant, melting temperature, and lattice anharmonicity in Si nanoparticles.
Article
Physics, Fluids & Plasmas
Marco A. Amaral, Marcelo M. de Oliveira
Summary: In this study, evolutionary game theory is used to model scenario with randomly perturbed payoffs, showing that payoff fluctuations induce slow dynamics and cooperation decay behaves as power laws. The emergence of Griffiths phase and symmetric Griffiths phase near defector's extinction point are observed, indicating their potential frequent occurrence in evolutionary game dynamics.
Article
Chemistry, Physical
Qilong Gao, Sen Zhang, Yixin Jiao, Yongqiang Qiao, Andrea Sanson, Qiang Sun, Xinwei Shi, Erjun Liang, Jun Chen
Summary: In this study, a new negative thermal expansion (NTE) material, CaSnF6, was synthesized by solvothermal method for the first time. The XRD and Raman spectroscopy results showed a phase transition from rhombohedral to cubic structure at about 200 K, accompanied by a significant isotropic NTE effect in the cubic phase. Lattice dynamics calculations revealed that the NTE is attributed to the transverse vibration of fluorine atoms excited by low-frequency phonons. This work not only expands the NTE family of fluorides, but also provides a new facile and low-cost fabrication method for NTE fluorides.
Editorial Material
Physics, Condensed Matter
K. Anand, M. P. Singh
Summary: The recent models used by Chandra for the volume dependence of the Gruneisen parameter of MgO yield inconsistent results for the third order Gruneisen parameter, which contradicts the thermodynamic constraint at extreme compression. Chandra's finding that the parameter increases with pressure is in contradiction with earlier studies based on seismic data, which showed a decrease with increasing pressure.
PHYSICA B-CONDENSED MATTER
(2022)
Article
Physics, Condensed Matter
Gora Dieye, Sameh I. Ahmed, Abdou C. Wade, Mamoudou Sall, Djibril Diop
Summary: The study directly evaluated the bond Gruneisen parameter of gallium arsenide using temperature-dependent EXAFS data, revealing a positive and weakly temperature-dependent linear characteristic. However, the model showed inadequacy in dealing with local properties, displaying significant differences from parameters obtained using other techniques.
SOLID STATE COMMUNICATIONS
(2021)
Article
Multidisciplinary Sciences
Tomas Kamencek, Benedikt Schrode, Roland Resel, Raffaele Ricco, Egbert Zojer
Summary: Metal-organic frameworks often exhibit significant thermal expansion coefficients, but MOF-74 shows a unique behavior. By combining density-functional theory calculations with the Gruneisen theory, researchers explain the small thermal expansion coefficients in MOF-74 and reveal their relationship with phonon frequencies.
ADVANCED THEORY AND SIMULATIONS
(2022)
Article
Materials Science, Ceramics
Xudong Wang, Ke Chen, Ziqian Li, Haoming Ding, Yujie Song, Shiyu Du, Zhifang Chai, Hui Gu, Qing Huang
Summary: A series of chalcogen-containing MAX phases, Hf2(SexS1_x)C, were successfully synthesized, and their lattice parameter change followed Vegard's law. The average coefficient of thermal expansion (CTE) could be continuously tuned by substituting Se for S, with Hf2(SexS1_x)C MAX phases having tunable CTE values ranging from 7.59 mu K_1 to 9.93 mu K_1. The substitution of Se effectively softened the crystal structures, as reflected by the longer average M-A bond in Sealloying Hf2(SexS1_x)C. Additionally, the CTEs along the a and c axes in all Hf2(SexS1_ x)C MAX phases were almost the same, indicating their potential application in thermal barrier coatings (TBC) that require isotropic volume change.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2023)
